Recently, portable devices (smartphones, tablet personal computers, personal digital assistants, etc.) have become widespread. Further, the portable device comprises an input sensor which detects a change in the capacitance. When a user's finger, for example, is brought close to a surface of a liquid crystal display panel of the portable device, the input sensor can detect position information of the user's finger as an operation input.
As the input sensor, an in-cell-type sensor which is incorporated into the interior of a liquid crystal display panel and an on-cell-type sensor which is disposed on the surface of a liquid crystal display panel are available.
In the in-cell-type sensor, a common electrode for liquid crystal driving (which is formed by indium-tin-oxide (ITO) having transparency) is used as a detection electrode element which constitutes the input sensor. Since the common electrode for liquid crystal driving is used as the detection electrode element of the input sensor, it is possible to prevent the thickness of the liquid crystal display panel from being increased and also to reduce the manufacturing steps for structuring the input sensor.